and as you know your monitor do not apply refresrates 60 is enough. Switch to 17'LCD default mode 1280x1024, to get an sharper picture, if that is what ACER suggests in the handbook and look there for the HorizSync! 32~80 kHz I think.
Here is my cut working XF86Config with nVidia drivers, nV AGP, Hyundai Flatpanel Imagequest L70S

Do not apply it. You must specify in the "ServerLayout" the right names like
"Default Layout" etc. for tyour devices.
And do not try all this frequency hell. Delete this. Its from older times or older monitors. They talk now with the DDC. And do not use dfp in the driver config, its only for a real digital Flatpanel connected to the DVI. Yours is analog.